Lately, I've seen several threads where I believed that it was possible the birds had a fungal infection rather than a contagious respiratory illness. It must be treated or it can be fatal, but it doesn't have the long lasting potential for flock devastation that something like CRD can have. In other words, it is not passed bird to bird like CRD, does not make them carriers of anything like CRD and other more devastating diseases. Long periods of hot and humid weather, in addition to what we were all doing to keep them cool, i.e., wetting down pens constantly and getting bedding and straw wet, etc, have set up situations that were ripe for fungi to grow and release spores into the air. The chickens, especially ones that are not as heat tolerant so they are panting more heavily than others, then breathe in these spores, which set up housekeeping in the lungs and cause pneumonia-like symptoms like deep, gurgly "coffee-pot" breathing. Usually, there are no discharges, just the congested sounding breathing, maybe some sneezing here and there or other odd sounds. You need to evaluate the circumstances, who is affected and who is not. In my flock, my hyperactive Delaware rooster actually turned purple more than once and couldn't catch his breath while chasing the hens and doing his normal stuff. He gurgled like he was going to choke any minute and we had to cool him down ASAP; he was one step away from dropping dead a couple of times before we realized what was wrong and thankfully, we were standing there both times to intervene. A week in the cool house, resting and being misted with Oxine AH in our cool mist vaporizer daily in 10 minute sessions, worked wonders. He's back with the flock. A few others were affected, mainly the most elderly hens and the ones who were compromised by molt or internal laying plus a few who just were panting horribly and could not tolerate the weather conditions they clearly were not used to. Only a handful of hens had to be treated in the house like the rooster did with the Oxine misting. The rest of the flocks did perfectly fine and those who didn't have symptoms were the ones who don't seem to have that much trouble in the heat, weren't molting, were fairly young, weren't stressed in any other way besides the heat. We have had three months of weather conditions that usually we have only three days of here in the mountains at my 2000 ft elevation, so my entire flock was very heat stressed. Even the nights didn't cool down as normal for our location. Just so you know, the state vet concurred with this diagnosis, says he's seen lots of stuff brought on by this unusual heat this summer. So, just wanted to put this out there for those who are dealing with some puzzling symptoms and are probably treating what they thought was CRD and wondering why antibiotics were not yielding satisfactory results for them. Below are links to two articles about fungal respiratory infections for you to read and which may help you assess this issue in your own flocks. I am no expert; this is the first time I've had to deal with anything like this, but I thought others might benefit from my experience this summer. http://chickencoop.maxupdates.tv/how-to-treat-upper-respiratory-fungal-infections/ http://www.shagbarkbantams.com/page11.htm ETA: With Oxine AH, do not add the citric acid activator! It makes it unsafe for the birds. You use it just by itself for misting your birds.